Senior Backend Developer (.NET/C#)

About the Position

We're seeking a Senior Backend Developer (.NET/C#) for a remote/hybrid role in Warsaw, Poland. Join our team to build and modernize mission-critical applications.

Responsibilities

• Develop new domain applications and modernize existing ones
• Continuously improve source code quality and apply good programming practices
• Design and implement efficient REST API interfaces
• Create unit tests and integration tests
• Actively participate in project, working, and status meetings in Agile/Scrum

Requirements

• University degree (mandatory)
• Minimum 5 years of overall experience on IT projects
• At least 3 years as a Backend Developer within the last 5 years
• Experience on IT projects with a value of at least 100,000 PLN net (mandatory)
• Practical knowledge of C# and .NET Core for web and desktop applications
• Ability to design and implement REST APIs
• Strong knowledge and practical use of design patterns and architectures: Clean Architecture, DDD
• Strong knowledge of relational databases (MS SQL, PostgreSQL): SQL query optimization, indexes, stored procedures
• ORM experience: Entity Framework Core, Dapper
• Experience implementing security mechanisms: authentication, authorization, and data encryption (JWT, OAuth2, FIDO2)
• Experience with Azure DevOps and Git version control
• English proficiency to read and write technical documentation

We Offer

• Long-term cooperation under a B2B contract
• Stable multi-month modernization project for critical domain systems at large scale
• Remote work with occasional Warsaw meetings
• Partner-like communication and full technical-organizational support during the contract

Salary

• 115-150 PLN/MONTH

About the Company

in4ge sp. z o.o. is a leading company in the technology sector, dedicated to delivering high-quality software solutions. We value innovation, teamwork, and professional growth.